The present invention relates to an apparatus for conveying sheets along a conveying path. The conveying path is bordered, on one side, by a light weight pivotal edge guide or a light weight pivotal edge guide and a fixed edge guide for controlling sheet cross-track and skew alignment.
Devices for advancing sheets over a conveying path, while bringing an edge of such sheets into contact with a fixed abutment to obtain cross-track and skew alignment, are known in the art. An example of this is disclosed in U.S. Pat. No. 4,546,964. In this patent, a conical member having flexible fingers is rotated about an axis extending orthogonal to the sheet conveying path. The flexible fingers exert a force, on the sheets, causing the sheets to advance both along the conveying path and laterally of the conveying path toward a fixed abutment or edge guide.
In U.S. Pat. No. 4,884,097 the fingers of the conical member in U.S. Pat. No. 4,546,946 are replaced by an undercut. The undercut permits compression of the roller, as it contacts and transports the sheet, thereby providing a component in the cross-track direction for moving the sheet laterally toward the abutment or fixed edge guide.
The above systems, while providing a simple means to obtain alignment, use fixed abutments or edge guides to obtain such alignment. Fixed abutments or edge guides, however, have a tendency to damage or mar sheets as the sheets make point contact with the fixed abutments or edge guides, no matter how gentle the drive system.